mineral

Chalcopyrite-bearing Ore

Chalcopyrite (CuFeS2)

Hardness: 3.5-4 (Mohs); Color: Brass-yellow to golden-yellow, often with iridescent tarnish; Luster: Metallic; Crystal Structure: Tetragonal; Cleavage: Poor/indistinct; Specific Gravity: 4.1-4.3

Hardness: 3
Color: Brass-yellow to golden-yellow, often with iridescent tarnish
Luster: Metallic

Identified March 21, 2026More mineral →

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Physical properties

Hardness: 3.5-4 (Mohs); Color: Brass-yellow to golden-yellow, often with iridescent tarnish; Luster: Metallic; Crystal Structure: Tetragonal; Cleavage: Poor/indistinct; Specific Gravity: 4.1-4.3

Formation & geological history

Primary mineral in hydrothermal veins, formed at high temperatures; also found in porphyry copper deposits and volcanogenic massive sulfide (VMS) deposits. Most significant deposits range from the Precambrian to Cenezoic eras.

Uses & applications

The primary ore of copper metal; also used as a gemstone (referred to as Peacock Ore when acid-washed for iridescence) and as a collector's mineral specimen.

Geological facts

Chalcopyrite is often called 'Fool's Gold' because of its yellow hue, though it is softer than Pyrite and more golden than real gold. It has been mined for over 5,000 years, providing the copper necessary for the Bronze Age.

Field identification & locations

Identify in the field by its brassy color, greenish-black streak (when rubbed on ceramic), and metallic luster. It is softer than steel and will scratch easily compared to pyrite. Commonly found in mining districts in Canada, Chile, and the United States (AZ, MT).